rename(2) - NetBSD Manual Pages

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RENAME(2)                 NetBSD System Calls Manual                 RENAME(2)


NAME

     rename -- change the name of a file


LIBRARY

     Standard C Library (libc, -lc)


SYNOPSIS

     #include <stdio.h>

     int
     rename(const char *from, const char *to);


DESCRIPTION

     rename() causes the link named from to be renamed as to.  If to exists,
     it is first removed.  Both from and to must be of the same type (that is,
     both directories or both non-directories), and must reside on the same
     file system.

     rename() guarantees that an instance of to will always exist, even if the
     system should crash in the middle of the operation.

     If the final component of from is a symbolic link, the symbolic link is
     renamed, not the file or directory to which it points.

     If both from and to are pathnames of the same existing file in the file
     system's name space, rename() returns successfully and performs no other
     action.


RETURN VALUES

     A 0 value is returned if the operation succeeds, otherwise rename()
     returns -1 and the global variable errno indicates the reason for the
     failure.


ERRORS

     rename() will fail and neither of the argument files will be affected if:

     [ENAMETOOLONG]     A component of a pathname exceeded {NAME_MAX} charac-
                        ters, or an entire path name exceeded {PATH_MAX} char-
                        acters.

     [ENOENT]           A component of the from path does not exist, or a path
                        prefix of to does not exist.

     [EACCES]           A component of either path prefix denies search per-
                        mission, or the requested link requires writing in a
                        directory with a mode that denies write permission.

     [EPERM]            The directory containing from is marked sticky, and
                        neither the containing directory nor from are owned by
                        the effective user ID.  Or the to file exists, the
                        directory containing to is marked sticky, and neither
                        the containing directory nor to are owned by the
                        effective user ID.

     [ELOOP]            Too many symbolic links were encountered in translat-
                        ing either pathname.

     [ENOTDIR]          A component of either path prefix is not a directory,
                        or from is a directory, but to is not a directory.

     [EISDIR]           to is a directory, but from is not a directory.

     [EXDEV]            The link named by to and the file named by from are on
                        different logical devices (file systems).  Note that
                        this error code will not be returned if the implemen-
                        tation permits cross-device links.

     [ENOSPC]           The directory in which the entry for the new name is
                        being placed cannot be extended because there is no
                        space left on the file system containing the direc-
                        tory.

     [EDQUOT]           The directory in which the entry for the new name is
                        being placed cannot be extended because the user's
                        quota of disk blocks on the file system containing the
                        directory has been exhausted.

     [EIO]              An I/O error occurred while making or updating a
                        directory entry.

     [EROFS]            The requested link requires writing in a directory on
                        a read-only file system.

     [EFAULT]           Path points outside the process's allocated address
                        space.

     [EINVAL]           from is a parent directory of to, or an attempt is
                        made to rename `.' or `..'.

     [ENOTEMPTY]        to is a directory and is not empty.

     [EBUSY]            from or to is the mount point for a mounted file sys-
                        tem.


SEE ALSO

     open(2), symlink(7)


STANDARDS

     The rename() function deviates from the semantics defined in ISO/IEC
     9945-1:1990 (``POSIX.1''), which specifies that if both from and to link
     to the same existing file, rename() shall return successfully and per-
     forms no further action, whereas this implementation will remove the file
     specified by from unless both from and to are pathnames of the same file
     in the file system's name space.

     To retain conformance, a compatibility interface is provided by the POSIX
     Compatibility Library (libposix, -lposix) which is also be brought into
     scope if any of the _POSIX_SOURCE, _POSIX_C_SOURCE or _XOPEN_SOURCE pre-
     processor symbols are defined at compile-time: the rename() function con-
     forms to ISO/IEC 9945-1:1990 (``POSIX.1'') and X/Open Portability Guide
     Issue 4, Version 2 (``XPG4.2'').


BUGS

     The system can deadlock if a loop in the file system graph is present.
     This loop takes the form of an entry in directory `a', say `a/foo', being
     a hard link to directory `b', and an entry in directory `b', say `b/bar',
     being a hard link to directory `a'.  When such a loop exists and two sep-
     arate processes attempt to perform `rename a/foo b/bar' and `rename b/bar
     a/foo', respectively, the system may deadlock attempting to lock both
     directories for modification.  Hard links to directories should be
     replaced by symbolic links by the system administrator.

NetBSD 5.2                     December 27, 2005                    NetBSD 5.2